Polar Vortex, Definition, Formation, Causes, Impacts, Diagram

Polar Vortex

The polar vortex is a strong wind current created by low pressure in the Arctic and Antarctic. It is important to note that the polar vortex is not a storm; it is a cold air current in the stratosphere, containing some of the coldest air on Earth. Strong west-to-east winds, moving over 161 kilometers per hour, keep this cold air contained. In the Northern Hemisphere, the vortex has two centers: one near Baffin Island in Canada and another in northeastern Siberia. The Southern Hemisphere’s vortex is usually centered around the South Pole.

Sometimes, changes in air pressure can weaken the “wall” of wind that holds the polar vortex, causing it to wobble. This allows cold air to escape, leading to frigid temperatures, sometimes below -18°C (0°F), in other regions, even reaching as far south as Florida. The Antarctic polar vortex is stronger and less likely to wobble compared to the one in the North.

Read More: El Nino and La Nina

Polar Vortex Diagram

The polar vortex grows and shrinks due to the movement of air and heat in the Arctic. In autumn, as the circumpolar winds speed up, the polar air rises into the stratosphere and forms a rotating air mass called the polar vortex. Here is an illustration of the polar vortex.

Polar Vortex Formation

The anticlockwise air movement that keeps the colder air close to the Poles is referred to as a “vortex.” Technically, the polar vortex refers to a band of winds that surrounds the Arctic and keeps the cold air trapped in the North. Gas dealers used to call it the “polar pig.” In winter, the polar vortex often strengthens in the Northern Hemisphere, sending cold air south with the jet stream. This can lead to severe cold spells in the U.S. during winter.

Polar Vortex Formed in Past

It has happened numerous times in the past (1977, 1982, 1985, and 1989), with the most recent instance taking place in January 2014. This is not exclusive to the United States. Cold waves also occur in parts of Europe and Asia. The polar vortex is an atmospheric feature located hundreds of feet above the ground. The main concern for people is how cold it gets as the polar vortex becomes stronger.

Read More: Pressure Belts

Polar Vortex Northern Hemisphere

Depending on its temperature, the air in the polar vortex in the Northern Hemisphere is referred to as polar air or Arctic air, with the Arctic air being the coldest. The atmosphere is substantially warmer south of the polar vortex, corresponding to sub-tropical air and, further south, tropical air. A zone of sharp temperature gradients, with temperatures falling to the north, separates the frigid air inside the vortex from the warmer air to the south.

The polar front jet stream, a relatively thin ribbon of exceptionally fast-moving air that flows mostly from west to east, is created by these high-temperature disparities. Therefore, the polar front jet stream’s location and the southern edge of the polar vortex essentially line up.

Read More: Atmospheric Circulation

Polar Vortex Impacts

The environment of Earth may be impacted by the following polar vortex-related events.

• When the polar vortex breaks up in the upper atmosphere, it can have strong effects on the environment, such as colder temperatures and harsh winters in the Eastern U.S., Western regions, and Northern Europe.
• Sudden warming in the stratosphere caused by the polar vortex can make the Arctic warm in both the stratosphere and troposphere. This warm air helps push cold air south, leading to colder winters in the Northern Hemisphere, especially in the Eastern U.S.
• The stratospheric warming can cause the wind pattern to change, allowing chilly air to move south. Since 1880, the average global temperature has risen by 0.8°C, while the Arctic has warmed by more than double that.

Read More: Types of Winds

Polar Vortex and Global Warming

The polar vortex is often connected to global warming. Many issues related to global warming are believed to be caused by the polar vortex. Since the 1880s, global temperatures have increased by about 0.8°C. The Arctic has warmed and melted over twice as fast because of the polar vortex. The Arctic region’s temperature little differs from that of the North Pole, North America, or other comparable places. The Polar Vortex gets perturbed and begins to split as the energy of the Jet Streams ascends.

Read More: Monsoon in India

Polar Vortex and Jet Stream

The polar vortex and polar jet stream are separate entities, despite the fact that they interact with one another. The polar jet stream moves northward when the polar vortex, which is up in the stratosphere (left globe), is very strong and stable. Arctic air is captured in these containers.

Read More: Tropical Cyclone

Polar Vortex and Natural Cycles

The Arctic Oscillation is a pattern of changing air pressure over the Arctic and nearby areas, linked to the polar vortex. When the Arctic Oscillation is in a positive phase, the polar vortex moves closer to the pole. In a negative phase, the vortex shifts south and becomes more wavy, making the ridges and troughs more noticeable. Some researchers think changes in the Northern Hemisphere vortex are connected to warming in the Arctic caused by the loss of sea ice. However, this connection is debated and is still being studied.

Read More: List of Major Local Winds

Polar Vortex UPSC

The USA and Europe recently experienced extreme cold January and February in the northeastern parts which is an unusual phenomenon. Scientists site the formation of the “polar vortex” has led to such unusual cold winters.

Polar vortexes are referred to as whirling cones of low pressure over the poles that are strongest in the winters due to stark differences in the temperature between the polar regions and the mid-latitudes.

The polar vortex spins in the stratosphere, 10 to 48 kilometres above the ground and the troposphere. A strong jet stream contains the polar vortex behaving as a boundary wall.

The strong jet checks the polar vortex from sliding south of the northern hemisphere. The polar vortex at times gets stronger and pushes jet-stream south and invades the northeast regions of the USA and Europe bringing severe cold. Retreating winters and the advent of summers weakens the polar vortex. This leads the polar vortex to withdraw and retreat back to the poles.

We have covered all the facts and information about the Polar Vortex in this post, which will aid UPSC candidates in their preparation. Additionally, the accompanying PDF has comprehensive notes on the topic of the Polar Vortex for UPSC candidates.

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